The senile and unproductive orchards attributed a declining trend of production because of unsuitable site and climate, cultivation of inter crops, inadequate nutrition’s, improper planting, undesirable planting materials, incidence of insect pest and disease and other biotic and a biotic stresses.
To overcome the problem of unproductive orchards research efforts were initiated to standardize a technology for restoring the production potential of existing plantations by a technique called Rejuvenation.
The present paper helps to understand the basics of rejuvenation techniques for senile and unproductive orchards to fetch quality fruit production with increased yield to meet the present and future requirement of a farmer.
The term ‘Rejuvenation’ means restoring the productive capacity of the fruit includes removal of old twigs. Rejuvenation restores the production potential of old, un-productive orchards by pruning of branches at different periodicity and at different severities.
It also helps in maintaining the manageable tree height with open architecture and canopy of healthy shoots with outwardly growth facilitating penetration and utilization of light.
Crowding and encroachment of trees with subsequent inefficient light utilization, is an obvious problem with older orchards, if trees are not well managed. The internal bearing capacity of trees also decreases with time, due to overshadowing of internal bearing wood.
Requirement of rejuvenation of Senile orchard:
The orchards required to be rejuvenated as they show decline in yield and quality of produce which may be attributed to any one of the following factors:
- Reduced photosynthetic surface area.
- Less number of productive shoots.
- High incidence of diseases and insect pests.
- Less penetration of sunlight due to overcrowding.
Objectives of rejuvenation of old orchard
- To enhance productivity and economic age of plant.
- To convert the inferior and low yielding varieties into superior and high yielding trees.
- To exploit the better root system of a plant to survive adverse soil and climatic conditions.
- To reduce gestation period of plant.
- To lessen the incidence of diseases and pests.
Principle of rejuvenation of orchards:
- Trees have latent buds which are activated by heading back of branches at certain point to put forth new sprouts which grow into branches forming fruiting area.
- When the branches are cut back, imbalance is created in root: shoot ratio as a result new shoots arise from plant to balance it.
Technique of rejuvenating senile orchards:
The rejuvenation technology involves the heading back of unproductive trees to the extent of 1.0 to 1.5 meter height above the ground level during May-June or December-February.
The objective of heading back is to facilitate production of new shoots from below the cut point and allow the development of fresh canopy of healthy shoots. The newly emerging shoots are allowed to grow up to 40-50 cm length and then further pruned for emergence of multiple shoots below the pruning point to modify the tree structure and maintain canopy size.
Profusely emerging shoots in the inner canopy are also pruned out to promote branching. After second pruning, multiple shoots developed which are capable of producing flower buds.
Procedure of rejuvenating Unproductive Orchards:
The process can be started in the month of December -January. In an unproductive orchard, mark the branches behead them by giving a clean cut to the limbs with a sharp saw to avoid bark splitting and retain 30cm stubs on 3-6 major limbs.
The beheading of branches should be done from base to the top. Cow dung slurry or copper oxichloride paste should be applied on cut portions. Several sprouts will emerge on these stubs.
Plough the orchard and prepare it for inter crops. Make basins below the plants and irrigate the plant and apply 1 kg urea per tree. Remove weeks sprouts, control foliage feeding insect pests and grow summer season inter crop.
One or two superior sprouts on each stub are selected and grafted with the desired cultivar, while remaining sprouts removed gently by giving a clean cut close to the stub so that these may not re-sprout. If any of these shoots are left they will overpower the newly sprouted grafts. This way one will have 6-12 grafted shoots. These grafts sprout within 20 days of grafting.
The shoot above the sprouted graft should be headed back by keeping only one whorl of old leaves in November. These leaves provide food to the newly sprouted graft. Newly sprouted grafts should be covered with rice trash or plastic bags to save the grafts from frost or severe winters in December.
The covers may be removed in February-March. While removing the covers, the polythene sheet used for tying the graft union should also be gently removed.
The old sprout above the graft union should also be re-cut, keeping only the newly sprouted grafts. Care should be taken that grafts should not get damaged since these cannot tolerate even small pressure.
For at least two years care should be taken so that no sprout come up on the tree limbs other than the grafted shoots. Top-worked trees come into bearing within five years, depending upon the grafted cultivar.
If the tree is older, it is better not to head back all the main branches simultaneously, to avoid a sudden shock to the tree, which could result in the splitting of the bark of the main stem.
The tree can be converted into a commercial variety in stages. With rejuvenation, the benefit of an established root system of the trees can be utilized profitably. These trees can bear a good crop for a number of years once more.
Rejuvenation is said to be essential for the trees in which quality and yield is reduced to such an extent that orcharding becomes non-economical.
It helps in restoring the production potential of old unproductive and diseased orchards in shortest possible duration than any other technique and sustaining the life of farmer without affecting his economy to a great extent.
Dr. Pooja Pant
Assistant Professor, Faculty of Agricultural Sciences,
SGT University, Gurugram, Haryana